An IR that is large enough to extend at least 1 inch (2.5 cm) beyond the elbow and wrist joints for a forearm projection is
a. needed to record the elbow and wrist on the image.
b. needed so the beam can be tightly collimated.
c. not a required positioning procedure.
d. needed only when a joint problem is suspected.
Question 2
An AP forearm projection obtained with the wrist and elbow in lateral rotation demonstrates
1. superimposed first and second metacarpal bases.
2. the proximal radius superimposed over the ulna by more than 0.25 inch (0.6 cm).
3. superimposed fourth and fifth metacarpal bases.
4. the proximal radius and ulna without superimposition.
a. 1 and 2 only
b. 1 and 4 only
c. 2 and 3 only
d. 3 and 4 only